The present invention relates to a mechanism of opening and closing an apparatus of thermally activating a thermally sensitive adhering sheet, particularly relates to a technology effective by being utilized in a thermally activating apparatus provided with a thermal head having a heat generating element as heating means.
Description of the Related Art
In recent years, there is a thermally activated sheet as one of sheets pasted on commodities (for example, printing media formed with a coating layer including a thermally active component on a surface thereof such as a thermally sensitive adhering sheet) which is used in a wide field of pasting, for example, POS sheet of food product, physical distribution and delivery sheet, medical sheet, baggage tag, display sheet of bottles and cans and so on.
The thermally sensitive adhering sheet is constituted by respectively forming a thermally sensitive adhering agent layer normally showing nonadhering performance and manifesting adhering performance by being heated on one face of a sheet-like base member and a printable face on other face.
There has been proposed a printer for such a thermally sensitive adhering sheet having a thermally activating apparatus for heating a thermally sensitive adhering agent layer by bringing a head having a plurality of resistors (heat generating elements) as a heat source provided on a ceramic base plate into contact with a thermally sensitive adhering label as in a thermal head utilized as a printing head of a thermal printer (Patent Document 1).
[Patent Document 1]
JP-A-11-79152
Meanwhile, the thermally activating apparatus constituting heating means by the thermal head is constructed by a constitution in which the adhering face of the thermally sensitive adhering sheet is directly heated by the thermal head and therefore, a portion of the adhering agent is liable to exfoliate to adhere to the thermal head or a platen roller. Therefore, the thermal head and the platen roller are provided with a necessity of cleaning and interchanging more than that of other part. However, owing to a type of bringing the thermal head into press contact with the platen roller and inserting the thermally sensitive adhering sheet between the thermal head and the platen roller to thereby heat by the thermal head, the thermal head and the platen roller are arranged to be considerably proximate to each other and therefore, unless an opening and closing mechanism for separating the thermal head and the platen roller is provided, operation of cleaning or interchanging the head is made to be difficult to carry out.
Meanwhile, when the thermal head is repeatedly subjected to a heating processing for activation, a peripheral temperature thereof is gradually elevated and therefore, in the thermally sensitive adhering sheet for the thermal printer, when paper after having been activated remains at a vicinity of the thermal head, there is a concern of coloring the thermally sensitive face. Hence, the inventors have investigated to provide a discharge roller on the downstream side of the thermal head and the platen roller.
As a result, it has been found that when the discharge roller is provided on the downstream side of the thermal head and the platen roller, the thermal head and the platen roller cannot sufficiently be separated from each other by a simple opening and closing mechanism for simply pivoting a head holder holding the thermal head and there poses a problem that operation of cleaning or interchanging the thermal head and the platen roller is made to be difficult to carry out.